Headrest

ABSTRACT

Provided is an adjustable headrest installed at an upper portion of a seatback of a chair which a user&#39;s head contacts characterized in that an ergonomic head-shaped recess is provided such that the recess is adjusted to be appropriate to different head sizes, head shapes, and neck shapes of users to conveniently seat the neck and the head, allowing the user to rest and sleep on the chair. 
     The adjustable headrest mounted on the chair includes an upper block having an upper recess concaved in the front thereof to seat the head, and a lower block disposed under the upper block and having a lower recess concaved in the front thereof to seat the neck. Here, the upper block and the lower block are movable relative to each other.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 200______, filed ______, 200______, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates to a headrest, and more particularly, to a headrest divided into upper and lower or left and right blocks, each of which can move forward/rearward, leftward/rightward, or upward/downward, capable of naturally supporting a user's neck and head to induce a convenient posture and provide comfort.

More specifically, the present invention relates to a headrest installed at an upper portion of a seatback, which a user's head contacts, and having a recess with an ergonomic head shape, so that the portion in which the head is received can be appropriately expanded according to a shape of the head or a thickness of the neck to stably and correctly support the neck and the head, preventing the neck from being tilted right or left.

In addition, the present invention relates to a headrest in which a front surface of the upper block is disposed behind a front surface of the lower block so that the user's neck and head can be naturally supported to induce a convenient posture, and the user's ears can be freely maintained, naturally supporting the user's neck and head to induce the convenient posture and provide comfort.

In addition, the present invention relates, to an adjustable headrest capable of naturally supporting the neck and the head of a user to induce a comfortable posture and provide comfort by forming a slit in the middle thereof such that the head rest can be expandable in forward/rearward and leftward/rightward directions.

2. Discussion of Related Art

In general, the cervical vertebrae stand in a substantially curved (C) shape in an erect posture. However, when the head and back are reclined on a seat for rest and sleep, the cervical vertebra hangs in the air, and the muscle supporting the cervical vertebra is released to tilt and twist the cervical vertebra in forward/rearward and leftward/rightward directions. In addition, due to a rounded shape of a rear portion of the head, the head cannot be easily fixed but easily leans and causes a neck-tilting phenomenon. Further, when an inclination of the neck and the head cannot be appropriately adjusted, tension and pain may occur in the neck muscles.

When a conventional chair or headrest in which these phenomena and inconveniences are not considered is used, pain and inconvenience in the neck and shoulders increase with the passage of time. Since a conventional chair does not have a technique capable of adjusting the headrest according to the sizes and shapes of all users' heads and necks, situations in which a user suffers from an unnatural and inconvenient state of the head and the cervical vertebra and a neck-tilting phenomenon are neglected, and basic problems of the chair related to the neck and the head have not been solved.

SUMMARY OF THE INVENTION

In order to solve these problems, the present invention provides an adjustable headrest having an ergonomic shape and function capable of basically solving unnatural and inconvenient postures of the neck and the head and a neck-tilting phenomenon.

The present invention is directed to an adjustable headrest mounted on a chair including: an upper block having an upper recess concaved in the front thereof to seat the head; and a lower block disposed under the upper block and having a lower recess concaved in the front thereof to seat the neck, wherein the upper block and the lower block are movable relative to each other.

In addition, the present invention is also directed to an adjustable headrest mounted on a chair including: an upper block having an upper recess concaved in the front thereof to seat the head; and a lower block disposed under the upper block and having a lower recess concaved in the front thereof to seat the neck, wherein a portion of the lower block projects forward from the upper block, and at least a portion of the upper block and the lower block is formed of at least one of latex foam, memory foam, urethane foam, and sponge.

In addition, The present invention is directed to an adjustable headrest including: an upper support having an upper recess configured to seat a head and formed in the front thereof; and a lower support disposed under the upper support and having a lower recess configured to seat a neck and formed in the front thereof, wherein a slit is formed in the upper support so that the upper support can be expanded and contracted about the slit in forward/rearward and leftward/rightward directions.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail example embodiments thereof with reference to the attached drawings, in which:

FIG. 1 is a perspective view showing a headrest in accordance with a first exemplary embodiment of the present invention, which is mounted on a chair;

FIG. 2 is an exploded perspective view showing an upper block and a lower block of the headrest in accordance with a first exemplary embodiment of the present invention;

FIG. 3 is an exploded perspective view showing the entire headrest in accordance with a first exemplary embodiment of the present invention;

FIG. 4 is a rear perspective view showing the upper block and the lower block of the headrest in accordance with a first exemplary embodiment of the present invention;

FIG. 5 is a rear perspective view showing a main frame to which the upper block and the lower block are coupled;

FIG. 6 is a perspective view showing a headrest in accordance with a second exemplary embodiment of the present invention, which is mounted on a chair;

FIG. 7 is an exploded perspective view showing an upper block and a lower block of the headrest in accordance with a second exemplary embodiment of the present invention;

FIG. 8 is a perspective view showing a main frame in accordance with a second exemplary embodiment of the present invention;

FIG. 9 is a view showing a leftward/rightward adjustment means of the headrest in accordance with a second exemplary embodiment of the present invention;

FIG. 10 is a side view showing a forward/rearward adjustment means of the headrest in accordance with a second exemplary embodiment of the present invention;

FIG. 11 is a cross-sectional view showing the forward/rearward adjustment means of the headrest in accordance with a second exemplary embodiment of the present invention, when seen from the top;

FIG. 12 is a cross-sectional view showing an angle adjustment means and a tilt adjustment means in accordance with a second exemplary embodiment of the present invention, when seen from the front;

FIG. 13 is a view showing the angle adjustment means in accordance with a second exemplary embodiment of the present invention;

FIG. 14 is a view showing the tilt adjustment means in accordance with a second exemplary embodiment of the present invention;

FIG. 15 is a view showing a headrest in accordance with a third exemplary embodiment of the present invention;

FIG. 16 is an exploded perspective view of the headrest in accordance with a third exemplary embodiment of the present invention with blocks separated from each other;

FIG. 17 is a perspective view showing an upper block and a leftward/rightward adjustment means of the headrest in accordance with a third exemplary embodiment of the present invention;

FIG. 18 is a perspective view showing a headrest in accordance with a fourth exemplary embodiment of the present invention;

FIG. 19 is a perspective view showing a headrest in accordance with a fifth exemplary embodiment of the present invention, which is mounted on a chair;

FIG. 20 shows an upper block and a lower block of the headrest in accordance with a fifth exemplary embodiment of the present invention;

FIG. 21 is a cross-sectional view of a tilt adjustment means and an angle adjustment means of the headrest in accordance with a fifth exemplary embodiment of the present invention, when seen from the front;

FIG. 22 is a view showing an internal structure of the tilt adjustment means of the headrest in accordance with a fifth exemplary embodiment of the present invention;

FIG. 23 is a view showing the angle adjustment means of the headrest in accordance with a fifth exemplary embodiment of the present invention;

FIG. 24 is a view showing a chair, to which the headrest in accordance with a fifth exemplary embodiment of the present invention is to be coupled;

FIG. 25 is a view showing a headrest in accordance with a sixth exemplary embodiment of the present invention, which is coupled to a chair; and

FIG. 26 is an exploded perspective view showing an upper block and a lower block of the headrest in accordance with a sixth exemplary embodiment of the present invention.

FIG. 27 is a perspective view showing an adjustable headrest in accordance with an exemplary embodiment of the present invention;

FIG. 28 is a view showing the adjustable headrest in accordance with an exemplary embodiment of the present invention, which is mounted on a seat;

FIG. 29 is a view showing an adjustable headrest in accordance with another exemplary embodiment of the present invention, which is mounted on a seat;

FIG. 30 is a plan view schematically showing an air bag, which is contracted in the adjustable headrest in accordance with another exemplary embodiment of the present invention; and

FIG. 31 is a plan view schematically showing the air bag, which is expanded in the adjustable headrest in accordance with another exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Hereinafter, an adjustable headrest in accordance with an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First Embodiment

FIG. 1 is a perspective view showing a headrest in accordance with an exemplary embodiment of the present invention, which is mounted on a receiving portion 11 formed in an upper portion of a chair 10, FIG. 2 is a view showing an upper block 100 and a lower block 200, which are separated from each other, and FIG. 3 is an exploded perspective view of the headrest in accordance with the embodiment. In addition, FIG. 4 is a rear perspective view of the upper block 100 and the lower block 200 of the headrest in accordance with the embodiment, and FIG. 5 is a rear perspective view of a main frame 300.

The headrest in accordance with the embodiment includes the upper block 100 and the lower block 200, the upper block 100 includes a right upper block 110 and a left upper block 120, and the lower block 200 includes a right lower block 210 and a left lower block 220.

An upper recess 130 having a substantially hemispherical groove conforming to the back of a user's head is formed in the middle of the upper block 100, and a lower recess 230 having an approximately semi-cylindrical groove is formed in the middle of the lower block 200. The back of the user's head is seated on the upper recess 130 and the user's neck is seated on the lower recess 230, preventing the neck from being tilted.

The right upper block 110, the left upper block 120, the right lower block 210 and the left lower block 220 include frames 112, 122, 212 and 222, and shock-absorbing members 111, 121, 211 and 221 coupled to the frames, respectively.

Referring to FIG. 2, the upper frames 112 and 122 of the upper block 100 include side plates 114 and 124, rear plates 113 and 123 disposed at rear ends of the side plates 114 and 124, and bottom plates 115 and 125 disposed at lower ends of the side plates 114 and 124 and the rear plates 113 and 123, respectively. The bottom plates 115 and 125 extend inward from the side plates 114 and 124 to a predetermined length and extend forward from the rear plates 113 and 123 to a predetermined length to form a substantial “

” shape. Forward/rearward sliding protrusions 116 and 126 lengthily extending in a forward/rearward direction project downward from the bottom plates 115 and 125, and forward/rearward adjustment rack gears 604 lengthily extending in the forward/rearward direction project rearward from the rear plates 113 and 123.

The lower frames 212 and 222 of the lower block 200 include side plates 214 and 224, rear plates 213 and 223 disposed at rear ends of the side plates 214 and 224, and bottom plates 215 and 225 disposed at lower ends of the side plates 214 and 224 and the rear plates 213 and 223, respectively. The bottom plates 215 and 225 extend inward from the side plates 214 and 224 to a predetermined length and extend forward from the rear plates 213 and 223 to form a substantial “

” shape. Leftward/rightward sliding protrusions 217 and 227 lengthily extending in a leftward/rightward direction project downward from the bottom plates 215 and 225, and forward/rearward sliding grooves 216 and 226 lengthily extending in a forward/rearward direction corresponding to the forward/rearward sliding protrusions are formed at upper portions of the side plates 214 and 224.

Meanwhile, the shock-absorbing members 111, 121, 211 and 221 may be desirably formed of an elastic member such as latex foam, memory foam, urethane foam, sponge, and so on. The resilient member may be manufactured through a foaming expansion molding method and then coated with a soft polyurethane resin on an outer circumferential surface thereof through post-processing, preventing intrusion of moisture and contamination.

A coating liquid, in which a 70% fiber adsorbent, a 200% waterproof agent, and a 100% antibiotic deodorizer are mixed, is applied on the polyurethane outer circumferential surface to prevent propagation of germs and maintain cleanliness.

However, when an envelope is used on the headrest, post-processing may be omitted.

Meanwhile, the right upper frame 112, the left upper frame 122, the right lower frame 212 and the left lower frame 222 may be formed of a plastic injection material or a metal.

As shown in FIG. 3, the main frame 300 is disposed under the lower block 200.

The main frame 300 includes a bottom plate 310 and a rear wall 320 extending upward from a rear end of the bottom plate 310.

Leftward/rightward sliding grooves 330 extending in a leftward/rightward direction are formed at left and right edges of the bottom plate 310, and leftward/rightward sliding protrusions 217 and 227 protruding downward from the lower frames 212 and 222 are inserted into the leftward/rightward sliding grooves 330.

In addition, a height adjustment rack gear 403 is coupled to a lower portion of the bottom plate 310.

A leftward/rightward adjustment means receiving portion 340, in which a leftward/rightward adjustment means 500 (described later) is received, is lengthily formed inside the rear wall 320 from side to side, and a forward/rearward adjustment means receiving portion 350, in which a forward/rearward adjustment means 600 (described later) is received, is lengthily formed in an upper portion of the leftward/rightward adjustment means receiving portion 340 from side to side.

Here, a right coupling hole 341 and a left coupling hole 342 are formed forward in predetermined middle positions of the leftward/rightward adjustment means receiving portion 340, and a right through-hole 351 and a left through-hole 352 are formed adjacent to both left and right ends of the forward/rearward adjustment means receiving portion 350 in a forward/rearward direction.

The upper block 100 and the lower block 200 can be adjusted upward/downward, leftward/rightward, and forward/rearward by a height adjustment means 400 (described later), the leftward/rightward adjustment means 500 and the forward/rearward adjustment means 600.

First, as shown in FIG. 3, the height adjustment means 400 includes a height adjustment handle 401, a height adjustment rod 402 coupled to the inside of the height adjustment handle 401, a height adjustment pinion gear (not shown) formed at the outside of the height adjustment rod 402, and a height adjustment rack gear 403 meshed with the height adjustment pinion gear (not shown) and lengthily extending upward and downward to be coupled to a lower portion of the bottom plate 310 at its upper end.

Accordingly, when a user rotates the height adjustment handle 401, the height adjustment rod 402 and the height adjustment pinion gear (not shown) are rotated. As the height adjustment pinion gear (not shown) is rotated to move the height adjustment rack gear 403 upward and downward, the main frame 300 is moved in an upward/downward direction to enable height adjustment of the headrest in the upward/downward direction.

Next, as shown in FIGS. 3 and 4, the leftward/rightward adjustment means 500 includes a leftward/rightward adjustment handle 501, a leftward/rightward adjustment rod 502 lengthily extending inward from the leftward/rightward adjustment handle 501 and having two screw gears 503 and 504 formed at predetermined middle positions thereof, and leftward/rightward adjustment projections 505 (see FIG. 4) projecting rearward from the right lower frame 212 and the left lower frame 222 having a screw gear formed in the inside thereof. A right screw gear 503 and a left screw gear 504 formed at the leftward/rightward adjustment rod 502 are spaced apart from each other and have gears formed in opposite directions.

Accordingly, when the user rotates the leftward/rightward adjustment handle 501 in one direction, the leftward/rightward adjustment rod 502, the right screw gear 503 and the left screw gear 504 are rotated, and thus, a gap between the leftward/rightward adjustment projections 505 is increased or reduced to effectively increase or reduce a gap between the left lower block 210 and the right lower block 220.

Next, as shown in FIGS. 3 and 5, the forward/rearward adjustment means 600 includes a forward/rearward adjustment handle 601, a forward/rearward adjustment rod 602 extending inward from the forward/rearward adjustment handle 601, two forward/rearward adjustment pinion gears 603 formed adjacent to both left and right ends of the forward/rearward adjustment rod 602, and forward/rearward adjustment rack gears 604 meshed with the forward/rearward adjustment pinion gears 603. The two forward/rearward adjustment pinion gears 603 are formed at positions corresponding to the right through-hole 351 and the left through-hole 352 shown in FIG. 3, respectively, and the forward/rearward adjustment rack gears 604 are inserted into the right through-hole 351 and the left through-hole 352 to be meshed with the forward/rearward adjustment pinion gears 603, respectively.

Accordingly, when the user rotates the forward/rearward adjustment handle 601, the forward/rearward adjustment rod 602 and the forward/rearward adjustment pinion gears 603 are rotated, and thus, the forward/rearward adjustment rack gears 604 move in the forward/rearward direction to move the upper block 100 in the forward/rearward direction.

Meanwhile, in mounting the headrest on the chair, a switch receiving slit 12 is formed through one side surface of the receiving portion 11, and the leftward/rightward adjustment rod 502 or the forward/rearward adjustment rod 602 passes through the switch receiving slit 12. The switch receiving slit 12 may have a tolerance such that the leftward/rightward adjustment rod 502 and the forward/rearward adjustment rod 602 can freely pass therethrough.

Hereinafter, an operational principle of the headrest in accordance with the embodiment having the above configuration will be described.

First, a user sits on the chair to seat his/her head on the upper recess 130 and his/her neck on the lower recess 230.

Here, when the headrest is higher or lower than a position of the head, the user rotates the height adjustment handle 401 to rotate the height adjustment pinion gear (not shown) and move the height adjustment rack gear 403 and the main frame 300 upward and downward, adjusting a height of the headrest.

Meanwhile, when a width of the upper recess 130 or the lower recess 230 is somewhat large or small, the user rotates the leftward/rightward adjustment handle 501 to rotate the right screw gear 503 and the left screw gear 504 formed at the outside of the leftward/rightward adjustment rod 502, and thus, the leftward/rightward adjustment projections 505 are spaced apart from or approach each other in a leftward/rightward direction to increase or reduce lateral gaps between the lower frames 212 and 222 and the upper frames 112 and 122.

Meanwhile, when the back of the user's head relatively protrudes or is flat and adjustment of the headrest in the forward/rearward direction is needed, the user rotates the forward/rearward adjustment handle 601 to rotate the forward/rearward adjustment pinion gears 603, and the forward/rearward adjustment rack gears 604 meshed therewith are moved in the forward/rearward direction to move the upper frames 112 and 122 coupled to the forward/rearward adjustment rack gears 604 in the forward/rearward direction, adjusting the headrest to a state in which the head or the neck is in comfort.

Meanwhile, in the embodiment, while the height adjustment pinion gear (not shown), the right screw gear 503 and the left screw gear 504, the forward/rearward adjustment pinion gear 603, and so on, are rotated by a manual operation of the handle, they may be rotated by an electric motor.

In addition, a sensor may be attached to the headrest to detect a size and a shape of the user's head so that the headrest can be automatically adjusted.

Meanwhile, in the embodiment, while the headrest is generally divided into four blocks and employs the height adjustment means 400, the leftward/rightward adjustment means 500, and the forward/rearward adjustment means 600 to enable adjustment in all directions including upward/downward, forward/rearward, and leftward/rightward directions, the headrest may be divided into two upper and lower blocks and selectively employ only necessary adjustment means, or the head rest may be divided into three blocks by dividing only the upper block into left and right blocks or dividing only the lower block into left and right blocks and selectively employ only necessary adjustment means.

Second Embodiment

FIG. 6 is a perspective view showing a headrest in accordance with the embodiment, which is mounted on a chair 10 a, FIG. 7 is a view showing an upper block 100 a and a lower block 200 a, which are separated from each other, and FIG. 8 is a view showing a main frame 300 a.

In the first embodiment, while the receiving portion 11 is formed in the upper portion of the chair 10 and the headrest is installed in the receiving portion 11, in the embodiment, the main frame 300 a is coupled to the chair 10 a to project upward from the chair 10 and blocks of the headrest are installed in the main frame 300 a.

As shown in FIGS. 6 and 7, the headrest in accordance with the embodiment includes the upper block 100 a and the lower block 200 a, the upper block 100 a includes a right upper block 110 a and a left upper block 120 a, and the lower block 200 a includes a right lower block 210 a and a left lower block 220 a.

An upper recess 130 a having a substantially hemispherical groove conforming to the back of the user's head is formed in the middle of the upper block 100 a, and a lower recess 230 a having a substantially semi-cylindrical groove is formed in the middle of the lower block 200 a. The back of the user's head is seated on the upper recess 130 a, and the user's neck is seated on the lower recess 230 a to prevent the neck from being tilted.

The right upper block 110 a, the left upper block 120 a, the right lower block 210 a and the left lower block 220 a include frames 112 a, 122 a, 212 a and 222 a and shock-absorbing members 111 a, 121 a, 211 a and 221 a coupled to the frames, respectively.

Referring to FIG. 7, the upper frames 112 a and 122 a of the upper block 100 a include side plates 114 a and 124 a, rear plates 113 a and 123 a disposed at rear ends of the side plates 114 a and 124 a, and bottom plates 115 a and 125 a disposed at lower ends of the side plates 114 a and 124 a and the rear plates 113 a and 123 a, respectively. The bottom plates 115 a and 125 a extend inward from the side plates 114 a and 124 a to a predetermined length and extend forward from the rear plates 113 a and 123 a to a predetermined length to form a substantial “

” shape.

Here, a leftward/rightward coupling protrusion 118 a protrudes leftward from the rear plate 113 a of the right upper frame 112 a, and a leftward/rightward coupling groove (not shown) into which the leftward/rightward coupling protrusion 118 a is inserted is formed in the rear plate 123 a of the left upper frame 122 a to be opened rightward.

In addition, forward/rearward sliding protrusions 116 a and 126 a are formed at the outsides of the side plates 114 a and 124 a of the right upper frame 112 a and the left upper frame 122 a, and fastening holes 117 a and 127 a are formed in the forward/rearward sliding protrusions 116 a and 126 a in a leftward/rightward direction.

Meanwhile, the lower frames 212 a and 222 a of the lower block 200 a include side plates 214 a and 224 a, rear plates 213 a and 223 a disposed at rear ends of the side plates 214 a and 224 a, bottom plates 215 a and 225 a disposed at lower ends of the side plates 214 a and 224 a and the rear plates 213 a and 223 a, and middle plates 216 a and 226 a disposed over the bottom plates 215 a and 225 a and substantially parallel to the bottom plates 215 a and 225 a. The bottom plates 215 a and 225 a and the middle plates 216 a and 226 a extend inward from the side plates 214 a and 224 a to a predetermined length and extend forward from the rear plates 213 a and 223 a to a predetermined length to form a substantial “

” shape.

Here, forward/rearward sliding slits 217 a and 227 a are cut out in the side plates 214 a and 224 a from front sides thereof and over the middle plates 216 a and 226 a. In addition, leftward/rightward adjustment holes 503 a having screw gears formed at inner surfaces thereof are formed in the side plates 214 a and 224 a and between the middle plates 216 a and 226 a and the bottom plates 215 a and 225 a.

Further, a leftward/rightward coupling protrusion 219 a protrudes leftward from the rear plate 213 a of the right lower frame 212 a, a leftward/rightward coupling groove (not shown) into which the leftward/rightward coupling protrusion 219 a is inserted is formed in the rear plate 223 a of the left lower frame 222 a to be opened rightward.

Furthermore, leftward/rightward sliding protrusions 218 a and 228 a lengthily extending in the leftward/rightward direction are formed to protrude from lower portions of the bottom plates 215 a and 225 a, respectively.

Meanwhile, the shock-absorbing members 111 a, 121 a, 211 a and 221 a may be desirably formed of an elastic member such as latex foam, memory foam, urethane foam, sponge, and so on. Here, the frame may be formed of a plastic injection material or a metal.

Among the shock-absorbing members, the upper shock-absorbing members 111 a and 121 a are coupled onto the bottom plates 115 a and 125 a of the upper frames 112 a and 122 a, and the lower shock-absorbing members 211 a and 221 a are inserted and coupled between the middle plates 216 a and 226 a and the bottom plates 215 a and 225 a of the lower frames 212 a and 222 a.

The upper frames 112 a and 122 a are mounted on the middle plates 216 a and 226 a of the lower frames 212 a and 222 a.

The upper block 100 a and the lower block 200 a of the headrest are coupled to the inside of the main frame 300 a, and as shown in FIG. 8, the main frame 300 a includes left and right side plates 310 a, a rear plate 320 a disposed at rear ends of the side plates 310 a, and a bottom plate 330 a disposed at rear ends of the side plates 310 a and the rear plate 320 a.

A forward/rearward adjustment housing 604 a (described later) is coupled to the outsides of the side plates 310 a, and forward/rearward sliding slits 311 a are lengthily formed in front of the forward/rearward adjustment housing in the forward/rearward direction.

In addition, through-holes 312 a through which leftward/rightward adjustment rods 502 a can pass are formed in the side plates 310 a. Further, an angle adjustment means 700 a configured to adjust an angle of the main frame 300 a is coupled to the side plate 310 a.

Furthermore, leftward/rightward sliding slits 331 a coupled to lower leftward/rightward sliding protrusions 218 a and 228 a of the bottom plates 215 a, 225 a of the lower frame 212 a and lengthily extending in the leftward/rightward direction are formed in the bottom plate 300 a.

Meanwhile, as shown in FIGS. 8 to 14, the headrest in accordance with the embodiment includes a leftward/rightward adjustment means 500 a, a forward/rearward adjustment means 600 a, an angle adjustment means 700 a, and a tilt adjustment means 800 a to enable adjustment in the leftward/rightward and forward/rearward directions, angular adjustment, and tilt adjustment.

First, as shown in FIGS. 8 and 9, the leftward/rightward adjustment means 500 a include leftward/rightward adjustment handles 501 a, leftward/rightward adjustment rods 502 a having screw gears formed at outer circumferences thereof, and leftward/rightward adjustment holes 503 a formed in the side plates 214 a and 224 a of the lower frames 212 and 222 a and having screw gears formed at inner circumferences thereof.

Accordingly, when the user rotates the leftward/rightward adjustment handles 501 a, the leftward/rightward adjustment rods 502 a are rotated, and thus, the screw gears formed at the outer circumferences of the leftward/rightward adjustment rods 502 a are meshed with the screw gears formed at the inner circumferences of the leftward/rightward adjustment holes 503 a to move the lower frames 212 a and 222 a leftward and rightward. Accordingly, as the leftward/rightward adjustment means 500 a installed at left and right sides are adjusted, a gap between the right lower block 210 a and the left lower block 220 a can be increased or reduced.

Here, the leftward/rightward sliding protrusions 218 a and 228 a of the lower frames 212 a and 222 a are slidably guided by the leftward/rightward sliding slits 331 a of the main frame 300 a.

Next, the forward/rearward adjustment means 600 a is shown in FIGS. 10 and 11, FIG. 10 showing a schematic side view of the forward/rearward adjustment means 600 a and FIG. 11 showing a cross-sectional view of the forward/rearward adjustment means 600 a when seen from the top.

The forward/rearward adjustment means 600 a includes a forward/rearward adjustment handle 601 a, a forward/rearward adjustment pinion gear 602 a coupled to the inside of the forward/rearward adjustment handle 601 a, a forward/rearward adjustment rack gear 603 a coupled to the forward/rearward adjustment pinion gear 602 a and extending in the forward/rearward direction, and a connecting pin 605 a configured to connect one end of the forward/rearward adjustment rack gear 603 a and the forward/rearward sliding protrusions 116 a and 126 a formed at the outside of the side plates 114 a, 124 a of the upper frames 112 a and 122 a.

Here, portions of the forward/rearward adjustment pinion gear 602 a and the forward/rearward adjustment rack gear 603 a are received in the forward/rearward adjustment housing 604 a attached to the side plates 310 a. In addition, the forward/rearward sliding protrusions 116 a and 126 a are inserted into the forward/rearward sliding slits 217 a and 227 a of the lower frames 212 a and 222 a and the forward/rearward sliding slit 311 a of the main frame 300 to be slid in the forward/rearward direction.

Accordingly, when the user rotates the forward/rearward adjustment handle 601 a, the forward/rearward adjustment pinion gear 602 a is rotated, and thus, the forward/rearward adjustment rack gear 603 a moves forward and rearward to move the upper frames 112 a and 122 a connected through the forward/rearward adjustment rack gear 603 a and the connecting pin 605 a in the forward/rearward direction.

Meanwhile, FIG. 12 shows a cross-sectional view of the angle adjustment means 700 a when seen from the front, and FIG. 13 shows an appearance and an internal structure of the angle adjustment means 700 a at left and right sides, respectively.

The angle adjustment means 700 a includes a housing 701 a, a receiving portion 702 a formed inside the housing 701 a, a ratchet wheel 703 a received in the receiving portion 702 a, a rounded-triangular switching member 704 a disposed under the ratchet wheel 703 a and rotated by an operation of a switching lever 707 a, two stoppers 705 a disposed at both left and right sides of the switching member 704 a, and springs 706 a configured to bias the stoppers 705 a against the switching member 704 a.

One ends of the springs 706 a are supported by a wall surface of the receiving portion 702 a and the other ends are supported by the stoppers 705 a to constantly bias the stoppers 705 a against the switching member 704 a. Accordingly, when the stoppers 705 a contact corners of the switching member 704 a, the stoppers 705 a are spaced apart from the ratchet wheel 703 a. However, when the switching member 704 a is rotated to contact one of the stoppers 705 a at its one side, rather than the corners, the inclined stopper 705 a is vertically disposed to contact the ratchet wheel 703 a.

When any one stopper 705 a is inserted between teeth of the ratchet wheel 703 a, while the ratchet wheel 703 a can be rotated in a direction of pressing the stopper 705 a toward the spring 706 a, the ratchet wheel 703 a cannot be rotated in a direction of pressing the stopper 705 a toward the switching member 704 a.

Meanwhile, the housing 701 a of the angle adjustment means 700 a lengthily extends upward and downward to be coupled to an outside of a housing of the tilt adjustment means 800 a (described later) at its upper portion and inserted into an upper portion of the chair to be coupled to the chair at its lower end.

Meanwhile, FIG. 12 shows a cross-sectional view of the tilt adjustment means 800 a, and FIG. 14 shows a side view of an internal structure of the tilt adjustment means 800 a.

The tilt adjustment means 800 a is generally used in a headrest of a vehicle, and has a function of moving forward to a predetermined distance and upward to a predetermined distance when a force is applied from a rear side to a front side.

The tilt adjustment means 800 a having the above function includes a housing 801 a, and pivot members 802 a and a spring 805 a received inside the housing 801 a. Here, upper ends of the pivot members 802 a are pivotally coupled to an inner surface of the housing 801 a through a hinge coupling portion 803 a, and lower ends are pivotally coupled to the angle adjustment means 700 a through another hinge coupling portion 804 a.

Accordingly, in a state in which the pivot members 802 a of the tilt adjustment means 800 a are inclined as shown in an upper side of FIG. 14, when a force is applied forward to the main frame 300 a, as shown in a lower side of FIG. 14, the pivot members 802 a are rotated to be vertically aligned to move the upper frame 120 a forward to a predetermined distance and upward to a predetermined distance.

As described above, the internal configuration and principle of the tilt adjustment means 800 a are generally used in the headrest for a conventional vehicle and the adjustment means 800 a described in the embodiment employ the configuration and principle generally used in the conventional vehicle, and thus, detailed description of the configuration and principle will be omitted.

Hereinafter, an operational principle of the headrest in accordance with the embodiment having the above configuration will be described.

A user sits on the chair to seat the head on the upper recess 130 a and the neck on the lower recess 230 a.

Here, when a width of the upper recess 130 a or the lower recess 230 a is somewhat large or small, the leftward/rightward adjustment handle 501 a is rotated to rotate the leftward/rightward adjustment rods 502 a having the screw gears formed at the outer circumferences thereof, and the screw gears formed at the inner circumferences of the fastening holes 503 a of the side plates 214 a and 224 a of the lower frames 212 a and 222 a are meshed with the screw gears formed at the outer circumferences of the leftward/rightward adjustment rods 502 a to simultaneously move the lower frames 212 a and 222 a and the upper frames 112 a and 122 a in the leftward/rightward direction, adjusting the width of the recesses 130 a and 230 a.

Meanwhile, when the back of the user's head relatively protrudes or is flat and adjustment in the forward/rearward direction is needed, the user rotates the forward/rearward adjustment handle 601 a to rotate the forward/rearward adjustment pinion gear 602 a, and thus, the forward/rearward adjustment rack gear 603 a coupled thereto is moved in the forward/rearward direction. As a result, a force is applied to the forward/rearward adjustment protrusions 116 a and 126 a coupled through the forward/rearward adjustment rack gear 603 a and the connecting pin 605 a in the forward/rearward direction, and thus, the upper frames 112 a and 122 a are moved in the forward/rearward direction to adjust the headrest such that the head or the neck is in comfort.

In addition, when angular adjustment of the main frame 300 a is needed, the user operates the adjustment levers 707 a of the angle adjustment means 700 a to middle positions such that the switching member 704 a is in a neutral position and the ratchet wheel 704 a is rotatable in the forward/rearward direction, rotates the main frame 300 a to a comfortable angle, and then operates the adjustment levers 707 a installed at both sides of the main frame 300 a in different directions to prevent further rotation.

Further, when tilt adjustment is needed, the main frame 300 a is pushed forward or rearward to pivot the pivot member of the tilt adjustment means 800 a and the main frame 300 a is moved in upward/downward and forward/rearward directions to a predetermined distance to perform to the tilt adjustment.

As a result, the user can adjust the upper block 100 and the lower block 200 to the most appropriate state for his/her body and head shapes such that the head can be supported in comfort.

Meanwhile, in the embodiment, while the leftward/rightward adjustment rod 502 a and the forward/rearward adjustment pinion gear 602 a are rotated by a manual operation of the handle, they may be rotated by an electric motor. In addition, angular adjustment of the main frame 300 a with respect to the chair 10 a may also be performed using an electric motor.

Further, in the embodiment, while the headrest is generally divided into four blocks and employs the leftward/rightward adjustment means 500 a and the forward/rearward adjustment means 600 a to enable adjustment in all directions including upward/downward, forward/rearward, and leftward/rightward directions, the headrest may be divided into two left and right or two upper and lower blocks and selectively employ only necessary adjustment means, or the head rest may be divided into three blocks by dividing only the upper block into left and right blocks or dividing only the lower block into left and right blocks and selectively employ only necessary adjustment means.

Furthermore, in the embodiment, while only one tilt adjustment means is installed between the chair 10 a and the main frame 300 a, one tilt adjustment means may be further installed between the upper frames 112 a and 122 a and the lower frames 212 a and 222 a to enable further angular adjustment between the upper frames 112 a and 122 a and the lower frames 212 a and 222 a.

Third Embodiment

FIG. 15 is a view showing a headrest in accordance with a third exemplary embodiment of the present invention, FIG. 16 is a view showing blocks of the headrest, which are separated from each other, and FIG. 17 is a rear perspective view of an upper block and a leftward/rightward adjustment means.

The headrest in accordance with the embodiment includes an upper block 100 f and a lower block 200 f, the upper block 100 f includes a right upper block 110 f and a left upper block 120 f, and the lower block 200 f includes a right lower block 210 f and a left lower block 220 f.

An upper recess 130 f having a substantially hemispherical groove conforming to the back of a user's head is formed in the middle of the upper block 100 f, and a lower recess 230 f having a substantially semi-cylindrical groove is formed in the middle of the lower block 200 f. The back of the user's head is seated on the upper recess 130 f and the user's neck is seated on the lower recess 230 f, preventing the neck from being tilted.

The right upper block 110 f, the left upper block 120 f, the right lower block 210 f and the left lower block 220 f include frames 112 f, 122 f, 212 f and 222 f, and shock-absorbing members 111 f, 121 f, 211 f and 221 f coupled to the frames, respectively.

The frames 112 f, 122 f, 212 f and 222 f may be formed of a plastic injection material or a metal and may have a substantially half-hemispherical inner surface, and the shock-absorbing members 111 f, 121 f, 211 f and 221 f may be desirably formed of an elastic member such as latex foam, memory foam, urethane foam, sponge, and so on.

Meanwhile, the right upper frame 112 f and the left upper frame 122 f have a substantially half-hemispherical inner surface, a coupling protrusion 113 f protrudes leftward from a rear end of the right upper frame 112 f, and a coupling groove (not shown) into which the coupling protrusion 113 f is slidably inserted is formed in a rear end of the left upper frame 122 f to be opened rightward.

In addition, leftward/rightward adjustment rods 502 f are coupled to rear sides of the right lower frame 212 f and the left lower frame 222 f, and threads are formed at outer circumferences of the leftward/rightward adjustment rods 502 f. When the right lower frame 212 f and the left lower frame 222 f are coupled to a main frame 300 f, the leftward/rightward adjustment rods 502 f pass through forward/rearward through-holes 321 f formed in the rear plate 320 f of the main frame 300 f.

Further, forward/rearward sliding protrusions (not shown) lengthily protrude downward from the right upper frame 112 f and the left upper frame 122 f in the forward/rearward direction, and the forward/rearward sliding protrusions are inserted into and guided by forward/rearward guide grooves 214 f and 224 f of the lower frames 212 f and 222 f.

Meanwhile, the right lower frame 212 f and the left lower frame 222 f have a substantially rectangular parallelepiped shape, a corner of which is removed in a substantially half-hemispherical shape, forward/rearward guide grooves 213 f and 223 f are lengthily formed in upper portions thereof in the forward/rearward direction, and upward/downward through-holes 214 f and 224 f are formed to pass through in the front thereof.

Forward/rearward adjustment rods 602 f of a forward/rearward adjustment means 600 f (described later) pass through the upward/downward through-holes 214 f and 224 f.

A coupling protrusion 215 f protrudes leftward from a rear end of the right lower frame 212 f, and a coupling groove (not shown) into which the coupling protrusion 215 f is inserted is formed at a rear end of the left lower frame 222 f to be opened rightward.

The main frame 300 f includes two side plates 310 f, a rear plate 320 f disposed at rear ends of the side plates, and a bottom plate 330 f disposed at left and right lower ends of the side plates 310 f and the rear plate 320 f.

Here, forward/rearward through-holes 321 f are formed to pass through the rear plate 320 f forward and rearward, and upward/downward through-holes 331 f are formed to pass through the bottom plate 330 f upward and downward.

The leftward/rightward adjustment rods 502 f of the leftward/rightward adjustment means 500 f pass through the forward/rearward through-holes 321 f, and the forward/rearward adjustment rods 602 f of the forward/rearward adjustment means 600 f pass through the upward/downward through-holes 331 f.

Meanwhile, the leftward/rightward adjustment means 500 f includes leftward/rightward adjustment handles 501 f and the leftward/rightward adjustment rods 502 f. In a state in which the lower block 200 f is coupled to the main frame 300 f, the leftward/rightward adjustment rods 502 f pass through the forward/rearward adjustment holes 321 f of the main frame 300 f to partially project from the outside of the rear plates 320 f of the main frame 300 f. Threads are formed at the projected portions, and the leftward/rightward adjustment handles 501 f are fitted onto the threaded portions.

Meanwhile, the forward/rearward adjustment means 600 f includes forward/rearward adjustment handles 601 f and the forward/rearward adjustment rods 602 f. The forward/rearward adjustment rods 602 f are fixed to lower ends of the right upper frame 112 f and the left upper frame 122 f, respectively, and sequentially pass through the upward/downward through-holes 214 f and 224 f of the lower frames 212 f and 222 f and the upward/downward through-holes 331 f of the main frame 300 f to partially project downward from the bottom plate 330 f of the main frame 300 f. Threads are formed at the projected portions, and the forward/rearward adjustment handles 601 f are coupled to the threaded portions.

Tilt adjustment means 800 f are attached to the outsides of the side plates 310 f of the main frame 300 f, and angle adjustment means 700 f are coupled to the outsides of lower ends of the tilt adjustment means 800 f.

Portions of the lower ends of the angle adjustment means 700 f lengthily extend downward to be inserted into fixing holes of the chair to couple the headrest in accordance with the embodiment to the chair.

Here, since the configurations and functions of the angle adjustment means 700 f and the tilt adjustment means 800 f are the same, overlapping description thereof will not be repeated.

Hereinafter, an operation method of the headrest in accordance with the embodiment will be described.

A user sits on the chair to seat the head on the upper recess 130 f and the neck on the lower recess 230 f.

Here, when a width of the user's head does not fit the width of the upper recess 130 f, the user releases the forward/rearward adjustment handle 501 f to adjust the gap between the right lower frame 212 f and the left lower frame 222 f, and then, fastens the forward/rearward adjustment handle 501 f, such that the lower block 200 f is fixed with an appropriate gap maintained.

Meanwhile, when the upper block 100 f is to be moved forward and rearward according to how much the back of the user's head protrudes, the user releases the forward/rearward adjustment handle 601 f to freely move the upper block 200 f forward and rearward, and then, rotates the forward/rearward adjustment handle 601 f at an appropriate position to fix the upper block 100 f on the lower block 200 f.

Fourth Embodiment

FIG. 18 is a view showing a headrest in accordance with a fourth exemplary embodiment of the present invention. The headrest in accordance with the embodiment includes an upper block 100 c and a lower block 200 c fixed to a lower portion of the upper block 100 c.

The upper block 100 c includes an upper recess 130 c having a substantially hemispherical groove formed in the middle thereof and conforming to the back of a user's head, and the lower block 200 c includes a lower recess 230 c having a semi-cylindrical groove formed in the middle thereof.

Here, a front surface of the upper block 100 c is stepped to be disposed behind a front surface of the lower block 200 c at both left and right sides of the upper recess 130 c.

Accordingly, a step surface 240 c is formed between the front surface of the upper block 100 c and the front surface of the lower block 200 c, and the step surface 240 c has an inclination increasing from a front side to a rear side.

Since the front surfaces of the upper block 100 c and the lower block 200 c are stepped such that the user's neck is supported by the lower recess 230 c to substantially prevent the neck from being tilted, the left and right outer sides of the upper recess 130 c on which the head is seated are somewhat cut out to free the ears so that the headrest can be used regardless of different widths of users' heads.

The upper block 100 c and the lower block 200 c may be integrally formed with each other.

Meanwhile, the upper block 100 c and the lower block 200 c are mounted on a main frame 300 c. The main frame 300 c includes two left and right side plates 310 c, a rear plate 320 c coupled to rear ends of the side plates 310 c, and a bottom plate 330 c coupled to lower ends of the side plates and the rear plate. The bottom plate extends inward from both left and right side plates to a predetermined length and extends forward from the rear plate to a predetermined length to form a substantial C shape.

Currently, frames of headrests for vehicles have been formed of a metal, a thin sponge has been attached to the outside of the frame, an outer cover has been put on the headrest, and then, the head has been coupled to a main body of the chair. On the other hand, in the embodiment, as shown in FIG. 18, the headrest having the recess, on which the neck and the head can be supported in comfort, is formed of a soft material such as latex and memory foam, an outer cover is put on the headrest, the headrest is mounted on the main frame 300 c, and then, the headrest is coupled to the main frame 300 c and the main body of the chair.

In a method of coupling the headrest to the main body of the chair as shown in FIG. 18, the tilt adjustment means 800 c and the angle adjustment means 700 c are installed at both side plates of the main frame 300 c, and the lower ends lengthily extending from the housing are inserted into fixing holes 14 d of the chair 10 d to be coupled to the chair 10 d as shown in FIG. 24.

Since the tilt adjustment means 800 c and the angle adjustment means 700 c have the same configurations and functions as the tilt adjustment means 800 d and the angle adjustment means 700 d of a fifth embodiment (described later), detailed description of the tilt adjustment means 800 d and the angle adjustment means 700 d will be described later through the fifth embodiment.

The upper block 100 c and the lower block 200 c may be desirably formed of an elastic member such as latex foam, memory foam, urethane foam, sponge, and so on.

Fifth Embodiment

FIG. 19 is a perspective view showing the headrest in accordance with the embodiment, which is mounted on the chair 10 d and FIG. 20 is a view separately showing an upper block 100 d and a lower block 200 d constituting the headrest in accordance with the embodiment.

The upper block 100 d in accordance with the embodiment includes an upper frame 120 d and an upper shock-absorbing member 110 d coupled to an upper portion of the upper frame 120 d.

The upper frame 120 d includes two left and right side plates, a rear plate coupled to rear ends of the side plates, and a bottom plate coupled to lower ends of the side plates and the rear plate. The bottom plate extends inward from the lower ends of both the left and right side plates to a predetermined length and extends forward from the rear plate to form a substantial C shape.

The upper shock-absorbing member 110 d is formed of an elastic material having a substantially rectangular parallelepiped shape, a front portion of which is partially removed in a substantially hemispherical shape. The portion removed from the upper shock-absorbing member forms an upper recess 130 d, on which the back of the user's head is seated and supported.

The lower block 200 d includes a lower frame 220 d and a lower shock-absorbing member 210 d coupled onto the lower frame.

The lower frame 220 d includes two left and right side plates, a rear plate coupled to rear ends of the side plates, and a bottom plate coupled to lower ends of the side plates and the rear plate. The bottom plate extends inward from the lower ends of both left and right side plates to a predetermined length and extends forward from the rear plate to a predetermined length to form a substantial C shape.

The lower shock-absorbing member 210 d is a substantially rectangular parallelepiped elastic member, a front upper portion of which is partially removed in an inclined shape and a front middle portion of which is partially removed in a substantially semi-cylindrical shape.

A step surface 240 d is formed at a portion formed by inclinedly removing the front upper portion from the lower shock-absorbing member 210 d, and a lower recess 230 d is formed at a portion formed by partially removing a front portion in a concave shape.

The upper shock-absorbing member 110 d and the lower shock-absorbing member 210 d may be desirably formed of an elastic member such as latex foam, memory foam, urethane foam, sponge, and so on. Meanwhile, the frames 110 d and 210 d may be formed of a plastic injection material or a metal.

The upper frame 120 d and the lower frame 220 d are coupled to an upper portion of the chair through an upper tilt adjustment means 900 d, a lower tilt adjustment means 800 d, and an angle adjustment means 700 d.

First, FIG. 21 shows a cross-sectional view showing the upper tilt adjustment means 900 d and the lower tilt adjustment means 800 d when seen from the front, and FIG. 22 shows an internal structure when seen from a right side thereof. The two tilt adjustment means 800 d and 900 d are generally used in the headrest for a vehicle. When a force is applied in the forward/rearward direction, the headrest moves to a predetermined distance in the forward/rearward direction and a distance in the upward/downward direction.

The upper tilt adjustment means 900 d having the above function includes a housing 901 d and a pivot member 902 d and a spring 905 d received in the housing 901 d. Here, an upper end of the pivot member 902 d is pivotally coupled to a hinge coupling portion 903 d, the hinge coupling portion 903 d and the housing 901 d are coupled to a lower side surface of the upper frame 120 d, a lower end thereof is pivotally coupled to another hinge coupling portion 904 d, and the other hinge coupling portion 904 d is coupled to an upper side surface of the lower frame 220 d.

Accordingly, as shown in FIG. 19, in a state in which the upper tilt adjustment means 900 d and the lower tilt adjustment means 800 d are aligned upward and downward, while the pivot member 902 d of the upper tilt adjustment means 900 d is disposed in an inclined state as shown in a left side of FIG. 22, when a force is applied rearward to the upper frame 120 d, as shown in a right side of FIG. 22, the pivot member 902 d is rotated to be vertically aligned and the upper frame 120 d is moved rearward to a predetermined distance and upward to a predetermined distance.

As described above, the internal configuration and principle of the tilt adjustment means 900 d are generally and widely used in headrests for vehicles. Since the embodiment employs the configuration and principle of the tilt adjustment means generally used in a vehicle, detailed description of the configuration and operational principle will be omitted.

While the internal configuration of the tilt adjustment means 900 d used in the embodiment is known, in accordance with the embodiment, as the tilt adjustment means 900 d is fixedly installed at the upper frame and the lower frame to enable tilt adjustment between the upper block 100 d and the lower block 200 d, the headrest can be adjusted into the most comfortable and stable state according to a shape of the back of the user's head through a forward/rearward adjustment operation of the upper frame. While the tilt adjustment means is one of widely used techniques, there is no example of the tilt adjustment means in which the headrest is divided into the upper and lower blocks to be adjusted to conform to the head.

Meanwhile, similar to the upper tilt adjustment means 900 d, the lower tilt adjustment means 800 d includes a housing 801 d, and a pivot member 802 d and a spring 805 d received in the housing 801 d.

Here, an upper end of the pivot member 802 d is coupled to a lower side surface of the lower frame 220 d through a hinge coupling portion 803 d, and a lower end thereof is coupled to a housing of the angle adjustment means 700 d. Accordingly, when the lower frame 220 d is pushed from a front side to a rear side, since the pivot member 802 d is rotated to move the lower frame 220 d upward to a predetermined distance and rearward to a predetermined distance, the headrest can be adjusted to conform to a shape of the neck.

Here, since the lower tilt adjustment means 800 d employs a known technique generally used in a headrest for a vehicle, detailed description thereof will be omitted. While the configuration of the tilt adjustment means 800 d and 900 d used in the embodiment is known, according to the embodiment, as the two tilt adjustment means 800 d and 900 d are used to enable further tilt adjustment between the upper block 100 d and the lower block 200 d, the headrest can be adjusted to the most comfortable and stable state according to a shape of the back of the user's head.

Meanwhile, FIGS. 21 and 23 show a structure of the angle adjustment means 700 d, FIG. 21 shows a cross-sectional view thereof when seen from the front, a right side of FIG. 23 shows a side view thereof, and a left side of FIG. 23 show an internal structure thereof, with a portion of a housing removed.

The angle adjustment means 700 d includes a housing 701 d, a receiving portion 702 d formed inside the housing 701 d, a ratchet wheel 703 d received in the receiving portion 702 d, a substantially rounded triangular switching member 704 d disposed under the ratchet wheel 703 d and rotated according to an operation of a switching lever 707 d, two stoppers 705 d disposed at both left and right sides of the switching member 704 d, and springs 706 d configured to bias the stoppers 705 d against the switching member 704 d.

One ends of the springs 706 d are supported by a wall surface of the receiving portion 702 d and the other ends are supported by the stoppers 705 d to constantly bias the stoppers 705 d against the switching member 704 d. Accordingly, when the stoppers 705 d contact corners of the switching member 704 d, the stoppers 705 d are spaced apart from the ratchet wheel 703 d. However, when the switching member 704 d is rotated to contact one of the stoppers 705 d at its one side, rather than the corners, the inclined stopper 705 d is vertically disposed to contact the ratchet wheel 703 d.

When any one stopper 705 d is inserted between teeth of the ratchet wheel 703 d, while the ratchet wheel 703 d can be rotated in a direction of pressing the stopper 705 d toward the spring 706 d, the ratchet wheel 703 d cannot be rotated in a direction of pressing the stopper 705 d toward the switching member 704 d.

Meanwhile, the housing 701 d of the angle adjustment means 700 d lengthily extends upward and downward to be coupled to an outside of a housing of the tilt adjustment means 800 d at its upper portion and inserted into a fixing hole 14 d of the chair 10 d to be coupled to the chair at its lower end, as shown in FIG. 24.

FIG. 24 is a view showing a chair, on which the headrest is to be mounted. In FIG. 24, reference numeral 15 d designates a reinforcement member, which functions to support the headrest to prevent the headrest from being damaged due to strong impact upon a traffic accident when the headrest is applied to a vehicle.

Hereinafter, an operation method of the headrest in accordance with the embodiment will be described.

A user sits on the chair shown in FIG. 19 to seat the neck on the lower recess 230 d and the head on the upper recess 130 d.

Here, since the neck is supported by the lower recess 230 d to prevent the neck from being tilted, even when a front surface of the upper block 100 d is disposed behind a front surface of the lower block 200 d, the head can be sufficiently fixed and supported, and the user's ears can be relatively free.

Meanwhile, the user can operate the angle adjustment means 700 d, the lower tilt adjustment means 800 d and the upper tilt adjustment means 900 d to adjust the headrest to a comfortable state.

First, the adjustment levers 707 d of the angle adjustment means 700 d installed at both of the side plates of the lower frame are operated to a middle position to dispose the switching member 704 d at a neutral position so that the ratchet wheel 703 d is rotatable in the forward/rearward direction, the lower frame 220 d is rotated to a comfortable angle, and both of the adjustment levers 707 d are rotated in different directions to prevent further rotation of the ratchet wheel 703 d.

Next, the lower tilt adjustment means 800 d is operated to move the lower block 200 d to an appropriate position, and the upper tilt adjustment means 900 d is operated to move the upper block 100 d to an appropriate position.

As a result, the user can adjust the upper block 100 and the lower block 200 to the most appropriate state to conform to his/her body and head shapes so that the head can be supported in comfort.

Sixth Embodiment

FIG. 25 is a view showing a headrest in accordance with a sixth exemplary embodiment of the present invention mounted on a chair.

The headrest in accordance with the embodiment includes an upper block 100 e and a lower block 200 e, and the lower block 200 e includes a right lower block 210 e and a left lower block 220 e.

An upper recess 130 e having a substantially hemispherical groove conforming to the back of a user's head is formed in the middle of the upper block 100 e, and a lower recess 230 e having a semi-cylindrical groove is formed in the middle of the lower block 200 e. The back of the user's head is seated on the upper recess 130 e and the user's neck is seated on the lower recess 230 e, preventing the neck from being tilted.

The upper block 100 e, the right lower block 210 e, and the left lower block 220 e include frames 120 e, 212 e and 222 e, and shock-absorbing members 110 e, 211 e and 221 e coupled to the frames, respectively.

Referring to FIGS. 25 and 26, the upper frame 120 e of the upper block 100 e includes two left and right side plates, a rear plate disposed at rear ends of the side plates, and a bottom plate disposed at lower ends of the side plates and the rear plate. The bottom plate extends inward from the side plates to a predetermined length and extends forward from the rear plate to a predetermined length to form a substantial “

” shape.

The upper shock-absorbing member 110 e is a substantially rectangular parallelepiped elastic member, a front upper portion of which is partially removed in a substantially hemispherical shape. The portion formed by partially removing the upper shock-absorbing member in a concave shape forms the upper recess 130 e and the back of the user's head is seated and supported on the upper recess 130 e.

Each of the lower frames 212 e and 222 e of the lower block 200 e includes a side plate, a rear plate disposed at a rear end of the side plate, and a bottom plate disposed at lower ends of the side plate and the rear plate. The bottom plate extends inward from the side plate to a predetermined length and extends forward from the rear plate to a predetermined length to form a substantial “

” shape.

Here, a leftward/rightward insertion protrusion 215 e protrudes leftward from the rear plate of the right lower frame 212 e, and an insertion groove (not shown) into which the insertion protrusion is inserted is formed in the rear plate of the left lower frame 222 e to be opened rightward.

In addition, leftward/rightward sliding protrusions 214 e and 224 e lengthily extending in the leftward/rightward direction protrude downward from the bottom plate.

Further, leftward/rightward adjustment holes 503 e are formed to pass through the side plates, and screw gears may be formed at inner circumferences of the leftward/rightward adjustment holes.

Meanwhile, the shock-absorbing members 110 e, 211 e and 222 e may be desirably formed of an elastic member such as latex foam, memory foam, urethane foam, sponge, and so on.

Meanwhile, the frames 120 e, 212 e and 222 e may be formed of a plastic injection material or a metal.

The upper shock-absorbing member 110 e of the shock-absorbing members is coupled onto the bottom plate of the upper frame 120 e, and the lower shock-absorbing members 211 e and 221 e are coupled onto the bottom plates of the lower frames 212 e and 222 e.

Meanwhile, the upper block 100 e and the lower block 200 e are received in an upper portion of a main frame 300 e.

The main frame 300 e includes two left and right side plates, a rear plate disposed at rear ends of the side plates, and a bottom plate disposed at lower ends of the side plates and the rear plate. Two leftward/rightward sliding grooves 301 e are lengthily formed in the bottom plate in the leftward/rightward direction.

The leftward/rightward sliding protrusions 214 e and 224 e of the lower frames 212 e and 222 e are inserted into the leftward/rightward sliding grooves 301 e.

Meanwhile, two left and right through-holes 302 e are formed at the side plates of the main frame 300 e, and leftward/rightward adjustment rods 502 e of a leftward/rightward adjustment means 500 e (described later) are inserted into the left and right through-holes 302 e.

In addition, an upper tilt adjustment means 900 e and a lower tilt adjustment means 800 e are coupled to outsides of the side plates of the main frame 300 e, and an angle adjustment means 700 e is coupled to a side surface of the lower tilt adjustment means 800 e.

A portion of an upper end of the upper tilt adjustment means 900 e is coupled to an outside of the side plate of the upper frame 120 e, and a portion of a lower end thereof is coupled to an outside of the side plate of the main frame 300 e.

A portion of an upper portion of the lower tilt adjustment means 800 e is coupled to a lower side of the upper tilt adjustment means 900 e from the outside of the side plate of the main frame 300 e, and a portion of a lower end thereof is coupled to the angle adjustment means 700 e.

A portion of an upper end of the angle adjustment means 700 e is coupled to the lower tilt adjustment means 800 e, and the lower end extending in a rod shape is inserted into holes formed at an upper portion of the chair to be coupled thereto.

Here, since the configurations and functions of the upper tilt adjustment means 900 e, the lower tilt adjustment means 800 e and the angle adjustment means 700 e are the same as in the fifth embodiment, repeated description thereof will be omitted.

Meanwhile, the leftward/rightward adjustment means 500 e includes leftward/rightward adjustment handles 501 e and leftward/rightward adjustment rods 502 e extending inward from the leftward/rightward adjustment handles 501 e and having screw gears formed at outer circumferences thereof. As shown in FIG. 26, the leftward/rightward adjustment rods 502 e extending inward from the leftward/rightward adjustment handles 501 e pass through the left and right through-holes 302 e of the main frame 300 e to be inserted into the leftward/rightward adjustment holes 503 e of the lower frames 212 e and 222 e. Here, since the screw gears are formed at the outer circumferences of the leftward/rightward adjustment rods 502 e and screw gears are also formed at inner circumferences of the leftward/rightward adjustment holes 503 e of the lower frames 212 e and 222 e, as the leftward/rightward adjustment handles 501 e are rotated to rotate the leftward/rightward adjustment rods 502 e, the lower frames 212 e and 222 e can be slid leftward and rightward.

Meanwhile, when the lower frames 212 e and 222 e are slid in the leftward/rightward direction, the leftward/rightward sliding protrusions 214 e and 224 e protruding downward therefrom are guided by the leftward/rightward sliding grooves 301 e formed in the bottom plate of the main frame.

Hereinafter, an operation process of the headrest having the above configuration will be described.

A user sits on the chair and leans his/her head on the headrest such that the head is seated on the upper recess 130 e and the neck is seated on the lower recess 230 e. Here, when angular adjustment is needed, similar to the above embodiment, the angle adjustment means 700 e is operated to adjust an angle of the main frame 300 e, and when tilt adjustment is needed, the main frame 300 e is moved rearward to be tilt-adjusted. In addition, when only tilt adjustment of the upper block 100 e is needed for a forward/rearward adjustment operation of the upper frame, a force may be applied rearward to the upper block 100 e to move the upper block 100 e upward to a predetermined distance and rearward a predetermined distance.

In addition, the leftward/rightward adjustment handle 501 may be rotated to increase or reduce a gap between the right lower block 210 e and the left lower block 220 e leftward and rightward.

Accordingly, the user can adjust the headrest to conform to a shape of the back of the user's head, a length of the neck or an angle of the neck such that the neck and the head can be supported in the most comfortable state.

Seventh Embodiment

FIG. 27 is a perspective view showing an adjustable headrest in accordance with an exemplary embodiment of the present invention.

The adjustable headrest in accordance with the exemplary embodiment includes an upper support 100 b and a lower support 200 b disposed under the upper support 100 b.

The upper support 100 b is provided with an upper recess 130 b in the front thereof, which is recessed in an approximately hemispherical shape like the back of a human head, and a rear recess 140 b in the rear thereof, which is deeply recessed toward the middle thereof in a leftward/rightward direction.

Thus, the upper support 100 b is configured so that a thickness thereof is thin in the middle thereof in a forward/rearward direction and is gradually increased toward opposite left and right ends thereof in the forward/rearward direction when viewed from the top.

Here, the upper support 100 b is provided with a slit 150 b in the middle thereof in the leftward/rightward direction which is cut open by a predetermined depth downward from an upper end thereof. The slit 150 b is cut out to a predetermined depth in the middle of the upper support 100 b in the leftward/rightward direction.

Meanwhile, the lower support 200 b located under the upper support 100 b is provided with a lower recess 230 b in the front thereof which is recessed in an approximately cylindrical shape. A user's neck is seated and fixed on the lower recess 230 b to prevent the neck from being tilted.

Left and right front surfaces of the lower recess 230 b of the lower support 200 b project from left and right front surfaces of the upper recess 130 b of the upper support 100 b. That is, the front surfaces of the upper support 100 b are retracted from the front surfaces of the lower support 200 b.

Accordingly, the front surfaces of the upper support 100 b and the lower support 200 b have a stepped shape to form a step surface 240 b, an inclination of which is gradually increased from a front side to a rear side thereof.

The reason for stepping the front surfaces of the upper support 100 b and the lower support 200 b is that the left and right portions of the upper recess 130 b in which the head is seated are cut out to free the ears because the user's neck is supported by the lower recess 230 b to sufficiently prevent the neck from being tilted.

Meanwhile, the upper support 100 b and the lower support 200 b may include a member having elasticity such as latex foam, memory foam, urethane foam, sponge, and so on.

FIG. 28 is a view showing the headrest having the above-mentioned configuration mounted on a chair 10 b. A receiving portion 11 b in which the headrest is received is formed in an upper portion of a seatback of the chair 10 b, and the headrest is held in and coupled to the receiving portion 11 b so that the headrest can be disposed in a usable manner.

Hereinafter, operations of the headrest in accordance with the embodiment will be described.

A user sits on the chair 10 b to seat his/her neck on the lower recess 230 b and his/her head on the upper recess 130 b.

As a result, the neck seated on the lower recess 230 b is naturally supported and prevented from being tilted in leftward/rightward and rearward directions. In addition, since the back of the head is seated on the upper recess 130 b to prevent leftward and rightward movement of the head, a neck-tilting phenomenon can be completely prevented.

Here, when the back of the user's head protrudes, since the upper recess 130 b can be expanded in the forward/rearward direction due to presence of the slit 150 b, the user's head can fit in the upper recess 130 b so that the user can more comfortably sit on the chair and the neck-tilting phenomenon can be prevented.

Eighth Embodiment

FIGS. 29 to 31 show a headrest in accordance with another exemplary embodiment of the present invention, FIG. 29 is a view showing the headrest in accordance with the embodiment mounted on the chair, and FIGS. 30 and 31 are plan views showing the headrest in accordance with the embodiment, when viewed from the top.

In the description of the embodiments, like reference numerals designate like elements throughout the specification.

The headrest in accordance with the embodiment includes an upper support 100 b and a lower support 200 b disposed under the upper support 100 b.

The upper support 100 b is provided with an upper recess 130 b in the front thereof, which is recessed in an approximately hemispherical shape like the back of a human head, and a rear recess 140 b in the rear thereof, which is symmetrical with respect to the upper recess 130 b and recessed in an approximately hemispherical shape.

Thus, the upper support 100 b is configured so that a thickness thereof is thin in the middle thereof in a forward/rearward direction and is gradually increased toward opposite left and right ends thereof in the forward/rearward direction when viewed from the top.

Here, the upper support 100 b is provided with a slit 150 b in the middle thereof in the leftward/rightward direction which is cut open by a predetermined depth downward from an upper end thereof. The slit 150 b is cut out to a predetermined depth in the middle of the upper support 100 b in the leftward/rightward direction.

Meanwhile, the lower support 200 b located under the upper support 100 b is provided with a lower recess 230 b in the front thereof which is recessed in an approximately cylindrical shape. A user's neck is seated and fixed on the lower recess 230 b to prevent the neck from being tilted.

Left and right front surfaces of the lower recess 230 b of the lower support 200 b project from left and right front surfaces of the upper recess 130 b of the upper support 100 b. That is, the front surfaces of the upper support 100 b are retracted from the front surfaces of the lower support 200 b.

Accordingly, the front surfaces of the upper support 100 b and the lower support 200 b have a stepped shape to form a step surface 240 b, an inclination of which is gradually increased from a front side to a rear side thereof.

The reason for stepping the front surfaces of the upper support 100 b and the lower support 200 b is that the left and right portions of the upper recess 130 b in which the head is seated are cut out to free the ears because the user's neck is supported by the lower recess 230 b to sufficiently prevent the neck from being tilted.

An air bag 160 b is disposed in the rear recess 140 b. The air bag 160 b is configured to receive air from an air supply means (not shown) to be expanded, or to discharge the air to be contracted.

Here, any means such as a manual rubber pump or an automatic pump may be used as the air supply means as long as the air can be supplied into the air bag 160 b.

FIG. 30 shows the air bag 160 b in a contracted state and FIG. 31 shows the air bag 160 b in an expanded state. In a state in which the air bag 160 b is contracted, the slit 150 b is increased in width and moved rearward by a weight of the user's head to provide an appropriate shape to the user whose head has a large diameter or the back of whose head protrudes. On the other hand, when the air bag 160 b is expanded, the slit 150 b is reduced in width and the rear recess 140 b is kept in an original state. Thus, it is possible to provide an appropriate shape to the user whose head has a small diameter or the back of whose head is flat.

Meanwhile, a retainer 170 b is disposed in the rear of the rear recess 140 b. The retainer 170 b may be a member to which a separate solid plate is attached to the rear of the rear recess 140 b to prevent separation of the air bag inserted into the rear recess 140 b of the upper support 100 b.

Meanwhile, the upper support 100 b and the lower support 200 b may include a member having elasticity such as latex foam, memory foam, urethane foam, sponge, and so on. The resilient member may be manufactured through a foaming expansion molding method and then coated with a soft polyurethane resin on an outer circumferential surface thereof through post-processing, preventing intrusion of moisture and contamination.

A coating liquid, in which a 70% fiber adsorbent, a 200% waterproof agent, and a 100% antibiotic deodorizer are mixed, is applied on the polyurethane outer circumferential surface to prevent propagation of germs and maintain cleanliness.

However, when an envelope is used on the headrest, post-processing may be omitted.

Hereinafter, operations of the headrest of the embodiment will be described.

A user sits on the chair 10 b to seat his/her neck on the lower recess 230 b and his/her head on the upper recess 130 b.

As a result, the neck seated on the lower recess 230 b is naturally supported and prevented from being tilted in leftward/rightward and rearward directions. In addition, since the back of the head is seated on the upper recess 130 b to prevent leftward and rightward movement of the head, a neck-tilting phenomenon can be completely prevented.

Here, when the user's head has a large diameter or the back of the user's head protrudes, the air in the air bag 160 b is discharged, and the slit 150 b is increased in width and moved rearward by the user's head to increase an volume of the upper recess 130 b so that the user's head is fitted to the upper recess 130 b to maintain a convenient state.

On the other hand, when the user's head has a small diameter or the back of the user's head is flat, the air is filled into the air bag 160 b to reduce the width of the slit 150 b to maintain the rear recess 140 b and the upper recess 130 b in an original state so that the user's head fits in the upper recess 130 b.

Accordingly, the user can sit on the chair in a more comfortable state and prevent the neck-tilting phenomenon.

Meanwhile, although the embodiment including the air bag 160 b is exemplified as the rear recess 140 b of the head rest including the retainer installed in the rear thereof, the headrest may not include the retainer but a front surface of the receiving portion 11 b of the chair 10 b may function as the retainer.

Here, the forward direction described in the embodiments means a direction that a user faces when the head is supported by the headrest.

While the invention has been shown and described with reference to certain example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. 

1. A headrest mounted on a chair, comprising: an upper block having an upper recess concaved in the front thereof to seat a head; and a lower block disposed under the upper block and having a lower recess concaved in the front thereof to seat a neck, the upper block and the lower block are movable relative to each other.
 2. The headrest according to claim 1, further comprising a forward/rearward adjustment means configured to slide the upper block and the lower block to relatively move the upper block and the lower block in a forward/rearward direction.
 3. The headrest according to claim 1 or 2, further comprising a main frame on which the upper block and the lower block are mounted.
 4. The headrest according to claim 3, wherein the upper block comprises an upper frame and a shock absorbing member received in the upper frame and coupled to the upper frame, the lower block comprises a lower frame and a shock absorbing member received in the lower frame and coupled to the lower frame, and the forward/rearward adjustment means comprises a forward/rearward adjustment pinion gear installed at the main frame, and a forward/rearward adjustment rack gear coupled to the upper frame to be meshed with the forward/rearward adjustment pinion gear.
 5. The headrest according to claim 4, wherein the main frame comprises a bottom plate and a rear wall extending upward from a rear side of the bottom plate, the upper block and the lower block are disposed in the front of the rear wall and installed over the bottom plate, a through-hole is formed to pass through the rear wall in a forward/rearward direction, and the forward/rearward adjustment rack gear passes through the through-hole to be meshed with the forward/rearward adjustment pinion gear.
 6. The headrest according to claim 5, comprising a forward/rearward sliding protrusion is formed at any one of a lower portion of the upper block and an upper portion of the lower block, and a forward/rearward sliding groove into which the forward/rearward sliding protrusion is inserted to be guided is lengthily formed in the other one in a forward/rearward direction.
 7. The headrest according to claim 1, comprising a leftward/rightward adjustment means configured to adjust widths of the upper block or the lower block.
 8. The headrest according to claim 7, further comprising a main frame on which the upper block and the lower block are mounted.
 9. The headrest according to claim 8, comprising the lower block includes a right lower block and a left lower block, the left lower block includes a left lower frame and a shock-absorbing member coupled to the left lower frame, the right lower block includes a right lower frame and a shock-absorbing member coupled to the right lower frame, and the leftward/rightward adjustment means comprise a leftward/rightward adjustment rod installed in the main frame and having two screw gears formed on an outer circumference thereof in opposite directions; and leftward/rightward adjustment protrusions having screw gears formed on inner circumferences thereof to be meshed with the screw gears of the leftward/rightward adjustment rod, and coupled to the right lower frame and the left lower frame, respectively, wherein the leftward/rightward adjustment protrusion of the right lower frame and the leftward/rightward adjustment protrusion of the left lower frame are moved in opposite directions by rotation of the leftward/rightward adjustment rod.
 10. The headrest according to claim 9, wherein the main frame comprises a bottom plate and a rear wall extending upward from a rear end of the bottom plate, the leftward/rightward adjustment rod is installed in the rear wall of the main frame, a left coupling hole and a right coupling hole are formed in the rear wall of the main frame to correspond to the two screw gears of the leftward/rightward adjustment rod, and the leftward/rightward adjustment protrusions protrude rearward from the left lower frame and the right lower frame to be inserted into the left coupling hole and the right coupling hole.
 11. The headrest according to claim 9, wherein leftward/rightward sliding grooves are lengthily formed in the main frame in a leftward/rightward direction, and leftward/rightward sliding protrusions inserted into the leftward/rightward sliding grooves protrude outward from the right lower frame and the left lower frame.
 12. The headrest according to claim 1, wherein a height adjustment rack gear is vertically coupled to a lower portion of the main frame, and the height adjustment rack gear is meshed with a height adjustment pinion gear to move the main frame upward and downward by rotation of the height adjustment pinion gear.
 13. The headrest according to claim 1, wherein the upper block comprises an upper frame and a shock absorbing member coupled to the upper frame, the lower block comprises a lower frame and a shock absorbing member coupled to the lower frame, the lower frame comprises side plates, a rear plate disposed at rear sides of the side plates, a bottom plate disposed at lower ends of the side plates and the rear plate, and a middle plate disposed over the bottom plate and spaced apart from the bottom plate, the upper frame is disposed over the middle plate of the lower frame, and a shock absorbing member is disposed between the middle plate and the bottom plate of the lower frame.
 14. The headrest according to claim 13, wherein forward/rearward sliding protrusions protrude outward from the side plates of the upper frame, and forward/rearward sliding slits into which the forward/rearward sliding protrusions are inserted and guided are formed in the side plates of the lower frame.
 15. The headrest according to claim 14, wherein forward/rearward sliding slits are formed in the side plates of the main frame in a shape corresponding to the forward/rearward sliding slits of the lower frame.
 16. The headrest according to claim 1, further comprising an angle adjustment means configured to enable angle adjustment between a chair and the headrest.
 17. The headrest according to claim 1, wherein at least a portion of the upper block and the lower block is formed of a material comprising at least one of latex foam, memory foam, urethane foam and sponge.
 18. The headrest according to claim 3, comprising an upward/downward through-holes are formed in the lower block and the main frame to correspond to each other, and the forward/rearward adjustment means includes a forward/rearward adjustment rod coupled to the upper block at its upper end and configured to project downward from the main frame at its lower end through the upward/downward through-holes of the lower block and the main frame, and a forward/rearward adjustment handle threadedly engaged with the forward/rearward adjustment rod at a lower portion of the main frame.
 19. The headrest according to claim 8, comprising the lower block includes a left lower block and a right lower block, a forward/rearward through-hole is lengthily formed in the main frame in a leftward/rightward direction to pass through the main frame in a forward/rearward direction, and the leftward/rightward adjustment means includes a leftward/rightward adjustment rod coupled to the left lower block and the right lower block at its front end and configured to project rearward from the main frame at its rear end through the forward/rearward through-hole of the main frame, and a leftward/rightward adjustment handle threadedly engaged with the leftward/rightward adjustment rod at a rear side of the main frame.
 20. A headrest mounted on a chair, comprising: an upper block having an upper recess concaved in the front thereof to seat a head; and a lower block disposed under the upper block and having a lower recess concaved in the front thereof to seat a neck, wherein a portion of the lower block projects forward from the upper block, wherein at least a portion of the upper block and the lower block is formed of a material comprising at least one of latex foam, memory foam, urethane foam and sponge.
 21. The headrest according to claim 20, wherein a front surface of the upper block and a front surface of the lower block are stepped to form a step surface, wherein the step surface is inclined upward from a front side to a rear side.
 22. The headrest according to claim 21, comprising the upper block and the lower block are formed integrally with each other,
 23. The headrest according to claim 20, wherein the upper block comprises an upper frame and a shock absorbing member received in the upper frame and coupled to the upper frame, the lower block comprises a lower frame and a shock absorbing member received in the lower frame and coupled to the lower frame, and wherein the shock absorbing member is formed of a material comprising at least one of latex foam, memory foam, urethane foam and sponge.
 24. The headrest according to claim 23, further comprising a tilt adjustment means coupled to the upper frame at its upper portion and coupled to the lower frame at its lower portion, wherein the tilt adjustment means enables relative movement of the upper frame and the lower frame in a forward/rearward direction.
 25. The headrest according to claim 24, further comprising an angle adjustment means configured to adjust an angle of the headrest.
 26. The headrest according to claim 24, wherein the lower block includes a right lower block and a left lower block, and the left lower block and the right lower block are movable in a leftward/rightward direction.
 27. The headrest according to claim 20, comprising the upper block and the lower block are movable relative to each other.
 28. An adjustable headrest comprising: an upper support having an upper recess configured to seat a head and formed in the front thereof; and a lower support disposed under the upper support and having a lower recess configured to seat a neck and formed in the front thereof, wherein a cutout portion is formed in the upper support so that the upper support can be expanded and contracted leftward and rightward about the cutout portion.
 29. The adjustable headrest according to claim 28, comprising the upper support has a rear recess formed in the rear.
 30. The adjustable headrest according to claim 28, wherein left and right sides of the upper recess of a front end of the upper support are disposed behind a front end of the lower support.
 31. The headrest according to claim 29, wherein an air bag is coupled to the rear recess so that the cutout portion moves forward and rearward and is widened or narrowed in a leftward/rightward direction as air is filled into the air bag or discharged therefrom.
 32. The adjustable headrest according to claim 28 or 29, wherein the upper support and the lower support comprise at least one of latex foam, memory foam, urethane foam, and sponge.
 33. The adjustable headrest according to claim 30, wherein the upper support and lower support are stepped to form a step surface between the upper support and lower support, the step surface is inclined upward from a front side to a rear side thereof. 